What is basal cell carcinoma?
Basal cell carcinoma is one of the most common types of skin cancer. It rarely spreads beyond the skin and is therefore less likely to be life-threatening compared to other cancerous growths (malignancy). Nevertheless it should be considered as a serious condition since it is cancer. The growths can cause extensive disfigurement by invading surrounding healthy tissue.
Generally the most commonly affected site is the head and neck area but in recent years it has been noted that the incidence of lesions occurring in other body parts, especially the torso, have also increased. The typical appearance of basal cell carcinoma is bumpy raised lesion. The main risk factor is prolonged exposure to direct sunlight over long periods of time.
In most instances the lesions of basal cell carcinoma appear on the sun-exposed parts of the body like head and neck area. The common presenting features of any type of skin cancer is the presence of a non-healing skin lesion which repeatedly bleeds. With basal cell carcinoma the lesion may look like a:
- Pearly white or waxy raised skin lesion: these lesions are often lined with blood vessels and tend to bleed.
- Flat, scaly, brownish patchy lesion most commonly located one the back or chest.
- Waxy scar-like lesion (rare): these are quite easy to overlook however this form is notorious to cause invasion to the adjacent area and lead to disfigurement.
Common complications of basal cell carcinoma include:
- Recurrence after treatment of the primary lesion.
- Increased risk of suffering from other type of skin cancer especially squamous cell carcinoma.
- Invasion into adjacent tissues (muscles, nerves even bones) but rarely does this type of cancer spread to distant organs (metastasis).
Older cells in the body are replaced at regular interval by new cells. These new cells are produced by the process of cell division (mitosis) and older cells die by the process of apoptosis. Apoptosis is the process of programmed cell death. Both the process of cell division and cell death are highly controlled by number of factors, particularly the genetic material (DNA).
Sometimes there is sudden irreversible change in the genetic material (DNA) controlling production of these factors leading to over- or underproduction of some of the regulating factors. This can lead to suppression of apoptosis and overstimulation of cell division resulting in the formation of growths.
Basal cells are located in the outermost layer of the skin, the epidermis. These cells produce new cells and push the older cells towards the surface and are eventually shed. Mutation in the basal cells leads to uninhibited division of the basal cells and production of abnormal, cancerous cells. The exact cause of mutation is not known but UV radiation in sunlight and tanning lamps are thought to have some role in causing mutation.
Common factors increasing the risk of basal cell carcinoma are chronic sun exposure, radiation exposure, lighter complexion, being male, a family history of skin cancer, using immunosuppressant drugs, chronic exposure to arsenic and suffering from certain rare genetic disorders like Gorlin-Goltz syndrome and xeroderma pigmentosum.
As with any cancer, the aim of treatment is to remove the malignant tumor and destroy all cancerous cells. The treatment options for basal cell carcinoma includes removal of the lesion by electrodissection and curettage, surgical excision (“cutting”) or freezing of the cancer lesion. Certain drugs like imiquimod and flurouracil may be applied topically (on the skin surface). Just as important as the treatment are the preventative measures to avoid recurrence. This should be included as part of the management program and continued throughout life.